Patent Document 1 discloses a conventional optical reflection device that is used in, e.g. a laser printer. The conventional optical reflection device includes a polygon mirror including a polygonal rotating body and mirrors provided on side surfaces of the rotating body. The polygon mirror rotates to sweep laser beam on a scan surface of a photosensitive drum.
Optical reflection devices have been demanded to have s small size as color laser printers have been put widely in the market and had a small size. In the conventional optical reflection device including the polygon mirror, the polygon mirror can hardly have a small size, and a driving device that drives the polygon mirror is separately required, hence preventing the conventional optical reflection device from having a small size.
Patent Document 1: JP11-281908A